Ketsu-Imoko, Butt Imoko appeared in one of the episodes of Gag Manga Biyori.
From Japanese historical texts. Shoutoku Taishi, traveling with Ono no Imoko, is having trouble writing his letter to the emperor of Sui, and briefly considers writing about his strange dream the night before. This is depicted as a torso-less Imoko with his head attached at the abdomen and "butt imoko" written next to him. Imoko rejects the idea, which unfortunately leads to the infamous opening that refers to Sui as "the land of the setting sun" being written instead.
